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Fintech entrepreneur financing decision: Does the Pecking Order Theory still apply?
No full textInternational audienceThe rise of fintech startups has transformed the financial landscape, offering innovative solutions that challenge traditional banking models. There is a nascent literature exploring their potential to revolutionize financial services. However, these ventures may also face significant challenges when it comes to accessing financing and launching their own operations. Contrary to previous studies, we investigate the Fintech entrepreneur financing decision by adopting a qualitative approach through in-depth semi-structured interviews and by focusing on the Pecking Order Theory
Sparklen: A Statistical Learning Toolkit for High-Dimensional Hawkes Processes in Python
No full textThis paper introduces Sparklen, a statistical learning toolkit for Hawkes processes in Python, designed to bring together efficiency and ease of use. The purpose of this package is to provide the Python community with a complete suite of cutting-edge tools specifically tailored for the study of exponential Hawkes processes, with a particular focus on highdimensional framework. It includes state-of-the-art estimation tools with built-in support for incorporating regularization techniques, and novel classification methods. To enhance computational performance, Sparklen leverages a high-performance C++ core for intensive tasks. This dual-language approach makes Sparklen a powerful solution for computationally demanding real-world applications. Here, we present its implementation framework and provide illustrative examples, demonstrating its capabilities and practical usage
Enhanced energy management of fuel cell electric vehicles using integral sliding mode control and passivity-based control
No full textInternational audienceThis study introduces a novel control strategy and energy management system for Fuel Cell Electric Vehicles (FCEVs), aimed at enhancing reliability and reducing maintenance costs without the need for a Load Current Sensor (LCS). Integrating Integral Sliding Mode Control (ISMC) with Passivity-Based Control (PBC), the method focuses on regulating DC bus voltage, smoothing Fuel Cell (FC) current, and optimizing power distribution between the FC and SC, even without load current information. Notably, it eliminates the need for a load current sensor, dispenses with the requirement of an observer or a low-pass filter to estimate the load admittance, and guarantees overall system stability. Simulation and Hardware-in-the-Loop (HIL) tests validate its effectiveness, demonstrating its potential to enhance the competitiveness of FCEVs within the automotive sector
The end of Low Emission Zones or the impossibility of restricting cars in cities without social justice
No full textInternational audienceLow emission zones are a response to air quality issues. However, they appear to be central to urban decarbonisation policies and a justification for promoting modal shift policies and supporting alternative modes to the car. Yet their ambition is limited by the social inequalities they raise. By studying the example of the Greater Paris low-emission zone in France, we will examine the notion of environmental justice in this public policy.Research on the subject focuses on different aspects of social inequalities in the face of this environmental policy, but without taking an integrated view of inequalities as a function of use and location. They point to a number of inequalities in isolation without succeeding in showing the overlapping inequalities that certain households may suffer. The aim of this research is to question the notion of justice surrounding this environmental policy. Benefits, constraints and capabilities will therefore be studied.On the one hand, we will be looking at the beneficiaries of exposure for resident and non-resident users of low-emission zones. It would appear, however, that if these restriction policies are to be accepted, they must also benefit the populations whose trips are restricted. We will also assess the social impact of this measure and evaluate which households are affected, not just in terms of ownership but also in terms of use. Finally, we are going to analyse the current modal shift potential as a function of people's place of activity. This will reveal more clearly the constraints on car use as a function of the modes available, and thus reveal territorial and social inequalities.Finally, a broader perspective will show why policies that target the greatest number of people, and especially the poorest, while excluding the richest from restrictions, threaten the place of environmental issues in society in general
The conundrum challenges for Research Software and Research Data in Open Science
No full textInternational audienceAbstractThe Borgman's conundrum challenges [1] have been initially formulated concerning the difficulties to share Research Data: which Research Data might be shared, by whom, with whom, under what conditions, why, and to what effects.In our previous work, we have proposed a Research Software Definition [2] with a formulation that we have adapted in order to propose a Research Data definition [3,4]. We have thus constructed a framework to understand and to explain Research Software and Research Data in the Open Science context [5].This framework is constructed in three stages: definition, dissemination, and evaluation of these research outputs [2,3,4], and it is now completed with answers to the Borgman's conundrum challenges for Research Data [3] and for Research Software [6].In this talk we will present our answers to the Borgman's conundrum challenges, and we will explain the comparison methodologies that we have developed in order to construct and to complete this Open Science framework.It is our understanding that to provide correct and clear answers to the conundrum questions will have, as a consequence, the improvement of Research Software and Research Data sharing and dissemination practices, which, in turn, will enhance trustworthiness, correctness, rigor, reproducibility, reusability and transparency in the research endeavor.This FOSDEM'25 presentation follows and extends our previous talks at FOSDEM: [FOSDEM'21] Free/Open source Research Software production at the Gaspard-Monge Computer Science laboratory. Lessons learnt. https://archive.fosdem.org/2021/schedule/event/open_research_gaspard_monge/ [FOSDEM'22] On the dissemination/evaluation loop for Research Software. https://archive.fosdem.org/2022/schedule/event/open_research_cdur/ ReferencesBorgman, C.L. The conundrum of sharing research data. J Am Soc Inf Sci Tec 2012, 63, 1059–1078. https://doi.org/10.1002/asi.22634 Gomez-Diaz, T.; Recio, T. On the evaluation of research software: the CDUR procedure [version 2; peer review: 2 approved]. F1000Research 2019, 8 1353. https://doi.org/10.12688/f1000research.19994.2Gomez-Diaz, T.; Recio, T. Research Software vs. Research Data I: Towards a Research Data definition in the Open Science context. [version 2; peer review: 3 approved]. F1000Research 2022, 11 118. https://doi.org/10.12688/f1000research.78195.2 Gomez-Diaz, T.; Recio, T. Research Software vs. Research Data II: Protocols for Research Data dissemination and evaluation in the Open Science context. [version 2; peer review: 2 approved]. F1000Research 2022, 11 117. https://doi.org/10.12688/f1000research.78459.2 Gomez-Diaz, T.; Recio, T. Towards an Open Science definition as a political and legal framework: on the sharing and dissemination of research outputs. POLIS 2020, N. 19. https://doi.org/10.58944/yuro5734. Version 3, 2021, available at https://zenodo.org/doi/10.5281/zenodo.4577065 Gomez-Diaz, T.; Recio, T. The conundrum challenges for Research Software in Open Science, Computers, 2024, 13(11), 302. https://doi.org/10.3390/computers13110302</ol
Simplified modeling of wooden vehicule restraint system to reduce calculation time
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Experimental and Numerical Analysis of Corrosion-Induced Cracking in Reinforced Concrete
No full textInternational audienceThe aim of this paper is to present the results of an experimental and numerical investigation into the degradation of reinforced concrete (RC) specimens subjected to an accelerated corrosion process using impressed current in the presence of chloride ions. The corrosion of the rebars was carried out using three current densities (50, 100, and 200 µA/cm2) and various exposure times. The experimental results characterised the internal degradation of the RC specimens through measurement of the corrosion product thicknesses at the steel–concrete interface; the widths, lengths and orientations of internal concrete cracks; and the external concrete crack widths. In addition, numerical modelling of the corroded RC specimens was conducted to describe the crack patterns. The comparison between the experimental and numerical results demonstrated a high degree of correlation, providing insights into the degradation process of RC specimens due to corrosion
Cement or press-fit? Impact of patellar fixation technique on outcomes after primary TKA: a systematic review
No full textInternational audienceIntroduction: The optimal fixation technique for patellar components in primary total knee arthroplasty (TKA); cemented versus press-fit, remains controversial. While early press-fit designs were associated with complications, second-generation implants with improved osseointegration features have renewed interest in cementless fixation. Methods: This systematic review included studies comparing cemented and press-fit patellar fixation in primary TKA. A comprehensive literature search identified 202 studies, of which eight met predefined inclusion criteria. Data were extracted on survivorship, revisions, complications, and patient-reported outcome measures (PROMs). Results: Across 1666 knees, survivorship was comparable between cemented and press-fit groups. Several studies reported 100% short-term survivorship in cementless cohorts. Four studies identified statistically significant PROM differences, but findings were inconsistent and context-dependent. No clear advantage was found for either fixation type in terms of overall pain, function, or satisfaction. Cementless patellae demonstrated no increased risk of aseptic loosening or patellar fracture. Complications were infrequent and more often reported in cemented groups. Discussion: These findings showed no significant difference in failure or PROMs between fixation methods. While surgical preference remains a driver of implant choice, current evidence does not support a universal superiority of one fixation method over the other
Cemented dual-mobility total hip arthroplasty cups in a custom-made acetabulum: a clinical and radiological evaluation
No full textInternational audienceBackground: Acetabular reconstruction during revision total hip arthroplasty (THA) with major bone loss is a complex surgical challenge. The combination of custom-made (CM) acetabular components with cemented dual mobility (DM) cups may improve postoperative outcomes in this context. This study aims to assess the clinical, functional, and radiological results of this surgical approach. Methods: We conducted a retrospective, single-center observational study including 16 patients (mean age 70 years) who underwent revision THA between May 2016 and December 2024 using a cemented DM cup in a CM acetabular component. All patients presented with Paprosky 3A or 3B defects, and 38% had a history of periprosthetic joint infection (PJI). Functional outcomes were measured using the Oxford Hip Score (OHS) and modified Harris Hip Score (mHHS) pre- and postoperatively. Radiographic assessment included measurement of the center of rotation (COR) deviation in both axes, as well as acetabular inclination and anteversion on postoperative CT scans. Implant survival was analyzed using Kaplan-Meier methodology. Results: At a mean follow-up of 16.2 months, overall implant survival was 75%, increasing to 93.8% when excluding isolated DM cup revisions. No postoperative infections were observed. OHS improved from 14.1 to 27.6 and mHHS from 27.4 to 52.7 (p < 0.001 for both). A significant negative correlation was observed between vertical (y-axis) COR deviation and functional scores (p < 0.01), highlighting the importance of restoring vertical COR. Mean inclination and anteversion were 41.2° and 29°, respectively, generally within target alignment zones. Discussion: The combination of cemented DM cups with CM acetabular components appears to be an effective technique in complex revision THA. Functional recovery and implant survivorship are consistent with the existing literature, and the absence of infection despite prior PJI history suggests benefit from a multidisciplinary approach. Restoration of vertical COR is a predictor of functional outcomes
The reaction of maleic anhydride with alkenes: a review on the mechanisms involved in the reaction of maleic anhydride with lipids
No full textInternational audienceMaleic anhydride is one of the most widely used anhydrides after acetic and phthalic anhydride and its market has grown rapidly over the last century. This compound is a versatile monomer widely used in industrial and commodity chemicals. It is interesting to note that it can be obtained from biosourced molecules such as furfural and 5-hydroxymethylfurfural. The maleinization reaction involves the addition of maleic anhydride molecules to unsaturated compounds, particularly lipids, without the need of solvents. This review article provides a comprehensive overview of the maleinization reaction, focusing on the mechanisms involved in these reaction with lipidic compounds, providing a state-of-the-art overview. The review covers various aspects of the maleinization process, including properties and industrial applications of maleic anhydride, current production methods, experimental setups, and characterization methods for the final products. Different mechanisms involved in the maleinization reaction, such as the Diels–Alder reaction, free radical reaction, and ene reaction, are discussed. The use of additives like catalysts and inhibitors to optimize the reaction is also explored. This review aims to consolidate existing knowledge on maleinization reactions, addressing contradictions in earlier literature and highlighting recent developments. By providing a comprehensive understanding of the maleinization process, this work supports the future development of maleinized compounds for various applications, including biobinders, bioplasticizers, biopolymer synthesis, paints, and coatings